The present invention relates to an improved photographic recording device for recording, on a photosensitive recording medium in the form of a film, video images obtained from a CT (Computer Tomograph) apparatus, a NMR (Nuclear Magnetic Resonance) apparatus, an ultrasonic diagnosis apparatus, or the like displayed on a CRT (Cathode-Ray Tube) screen. More particularly, the invention relates to an improvement in such a device which includes a pair of lenses having different focal lengths and which are alternating disposed in an optical path.
In such a device as mentioned above, the lens system must have an optical axis which coincides with the optical path of the device. In switching between lenses, the optical axis of the lens disposed in the optical path must always be made to coincide with the center axis of the optical path of the recording device. In order to realize such coincidence between the optical axes of the lenses and the optical path of the optical system of the recording device, a precisely machined and precisely assembled lens switching mechanism and/or servo mechanism has heretofore been required, which is disadvantageous in view of manufacturing cost.